ActionCable Issues

gistfile1.txt

module ApplicationCable
  class Connection < ActionCable::Connection::Base
    identified_by :current_admin

    def connect
      self.current_admin = find_verified_admin
      logger.add_tags 'ActionCable', current_admin.email
    end

    protected

    def find_verified_admin # this checks whether a admin is authenticated with devise
      if verified_admin = env['warden'].admin
        verified_admin
      else
        reject_unauthorized_connection
      end
    end
  end
end

the error is 

There was an exception - NoMethodError(undefined method `admin' for #<Warden::Proxy:0x00000005c99eb0>)
/home/ubuntu/workspace/blog/app/channels/application_cable/connection.rb:13:in `find_verified_admin'